Ni-based single crystal superalloys for turbine blades experience multimodal creep. Current microstructural design lacks tailored γ-γ′ microstructures for specific conditions. Five initial microstructures with similar morphology and varying γ′ size were creep tested under 980°C/250 MPa and 1100°C/137 MPa. Both conditions showed single-peak creep life evolution, but the creep life peak shifted toward smaller γ′ sizes under the higher temperature. This shift arises from coupled effects of γ′ size on dislocation motion, lattice misfit on interfacial dislocation density and extra damage from TCP phase, offering insights for optimizing microstructures under complex service conditions.

Thermo-mechanical coupling during service induces distinct oxidation behavior in Inconel 718 superalloys. This study systematically examines the oxidation response under pre-tension and pre-compression strains, focusing on microstructural evolution and stress-type-dependent mechanisms. Results reveal that tensile strain suppresses oxidation via accelerated Cr outward diffusion forming protective Cr2O3, which reduces oxidation rate. While compressive strain promotes oxidation through void-enhanced oxygen penetration. These findings provide critical insights for designing oxidation-resistant superalloys under coupled stress environments.

A Ni2P layer on Ni nanorod arrays is used to elucidate the dynamic coupling between alcohol oxidation (AOR) and oxygen evolution (OER). A cooperative region (1.50-1.56 V vs. RHE, [OH-] < 2.0 M) boosts both TOFAOR and TOFOER, whereas a competitive region at higher potential/alkalinity suppresses AOR and compromises overall anodic performance. In situ Raman identifies NiOOH as the common active phase and reveals a complementary mechanism: OER enables NiOOH activation, while AOR drives NiOOH ordering and stabilizes the reconstructed interface, thereby mitigating Ni2P corrosion and sustaining higher currents. These insights provide practical guidance to engineer robust, low-energy, value-added anodes via controlled AOR-OER coupling.

This study explores a novel heat treatment process to encourage gamma/gamma(y) interface chemical segregation in a Ni-based single crystal superalloy and investigates the influence of such segregation on the creep life of the alloy. It was found that the specially designed heat treatment process is able to induce Co, Cr and Re segregation at the gamma/gamma(y) interface without affecting the cuboidal morphology of the gamma(y) phase. As a result, the alloy demonstrates much improved creep resistance, with a creep life improvement by 238 % when tested at 760 degrees C/800 MPa. The segregation is also found to reduce dislocation mobility and to slows the gamma(y) phase coarsening rate. With temperature rising, the formation of rafted structures may attenuate these benefits, leading to smaller incremental gains. These findings provide new insights for advancing heat treatment optimization in superalloys.

Interfaces such as grain boundaries, phase interfaces, precipitate/matrix interfaces and defect/matrix interfaces disrupt long-range atomic arrangement order and elemental distribution continuity. Reinforcing interfaces to enhance their mechanical performance and corrosion resistance is essential for their application in harsh service environments. The interfaces of numerous alloys have been mechanically enhanced by processing or element control. In most instances, interfaces still serve as initial oxidation sites, degrading the overall properties of the alloy. Hence, improving the corrosion resistance of an interface is still necessary to improve their applicability. In particular, for Inconel 718 alloys, a primary failure scenario is corrosion-induced failure in harsh working environments, such as high-temperature coupled oxygen-rich environments. This type of failure is normally considered to be initiated from the high quantity of delta/matrix phase interfaces. However, the understanding of the oxidation mechanisms and dynamics initiated at the delta/matrix phase interface is still limited because of a lack of in situ high spatial resolution studies. Here, the thermal oxidation behavior of the semicoherent delta/matrix interface in the Inconel 718 alloy is studied via aberration-corrected environmental transmission electron microscopy (ETEM). The dynamic evolution of the two-phase interface down to the atomic scale is revealed via in situ experiments. Preferential oxidation from the delta/matrix phase interface occurs at relatively low temperatures. Moreover, selective oxidation induces mutual mass transfer on both sides of the interface. Combined with the findings from molecular dynamics simulations, the results confirm that the semicoherent delta/matrix boundary exhibits a large lattice misfit and high energy, which ultimately facilitates the preferential oxidation of the interface. This work provides direct experimental data on the stress corrosion of superalloys and offers reference data for material design and improvement.

Paracrystallization provides a route to achieving synergistic properties beyond conventional property trade-offs, but applying it to layered materials is challenging due to strong bonding anisotropy. Here, we report the synthesis of paracrystalline graphite, a paracrystalline state realized in a layered material, through a high-pressure-driven “local graphitization” of C60 crystals. Structural characterization and reverse Monte Carlo simulations reveal a three-dimensional network of graphite-like clusters with ~70° interlamellar angles. This architecture delivers a combination of properties, including an isotropic hardness of 33.7 GPa, a plastic strain of 12% enabled by bond conversion and cluster reorganization, and weakly temperature-dependent semimetallic conductivity that varies by less than 12% from 4 to 450 K. Bridging the gap between crystalline graphite and noncrystalline carbon, this paracrystalline system demonstrates a viable pathway for designing materials with tailored multifunctional properties by engineering medium-range order. The authors synthesize paracrystalline graphite with a three-dimensional interwoven graphitic network. It combines a hardness of 33.7 GPa, a plastic strain of 12% and semimetallic conductivity varying by less than 12% from 4 to 450 K.

Water vapor plays a pivotal role in both the crystallization of CsPbBr-based perovskites and the operational stability of devices incorporating these materials. However, previous studies on this topic have been limited to indirect ex situ observation. Here, we utilize in situ environmental scanning electron microscopy (ESEM) to directly monitor the dynamic growth of CsPbBr-based perovskite at a water vapor pressure of 609 Pa (equivalent to 75% relative humidity at 4 degrees C) under a controlled gas atmosphere. Our real-time in situ observation captures the concomitant and direct crystallization of CsPb2Br5 and CsPbBr3, challenging the conventional phasetransition-mediated formation pathway. Furthermore, we demonstrate that the dual emission in the mixture of CsPbBr3 and CsPb2Br5 originates from distinct emissive centers, in contrast to the self-absorption and reemission mechanism in rod-like CsPbBr3. These findings offer direct evidence of water-vapor-mediated crystallization and their impact on material performance, thereby paving the way for both the design of environmentally stable perovskite-based devices and future ESEM investigations into complex multiphase processes.

The competitive adsorption between H* and OH* on single active sites is a long-standing bottleneck limiting alkaline hydrogen evolution reaction (HER) kinetics. Herein, we integrate "multi-element electronic regulation" with "dual-site functional partitioning" in a PtRuFeCoNi high-entropy alloy (HEA) electrocatalyst, which is synthesized via high-entropy engineering strategy. Driven by electronegativity differences among Pt, Ru, Fe, Co, and Ni, spontaneous electron transfer precisely modulates their d-band centers of Pt and Ru. This electronic regulation results in that Pt sites activate H2O and adsorb OH*, while Ru sites optimize H* adsorption free energy to -0.18 eV for selective H* stabilization. Operando EPR directly captures ·H's "generation-stabilization-conversion" dynamics, filling the characterization gap. Complemented by in situ Raman and FTIR, the dual-site mechanism is validated. PtRuFeCoNi/catalyst exhibits an ultra-low overpotential of 5.2 mV at 10 mA cm-2, a Tafel slope of 45.6 mV dec-1, and 150 h stability in 1 M KOH. For overall water splitting, it achieves 10 mA cm-2 at 1.41 V, outperforming Pt/C||RuO2. This work establishes a new paradigm for resolving intermediate adsorption competition in multi-electron transfer reactions.

Understanding the plastic behavior at crack tips is critical for enhancing the fracture toughness of nanometals. Although extensive research has been conducted, most previous studies have focused on pure metals, and how the crack tips accommodate plastic deformation in highly concentrated solid-solution alloys remain unclear due to limited atomic-scale evidence. In this study, the atomic-scale plastic behavior of crack tips in face-centered cubic (FCC) AuCu nanocrystals is investigated in situ. The results provide direct evidence that plastic deformation is governed by sequential activation of different deformation mechanisms, i.e., full dislocation activities first, then followed by random twinning/detwinning, and finally dislocation-twin interactions, which are rarely observed in pure metals. These deformation processes collectively enhance the fracture toughness of the nanocrystals, representing a previously unrecognized mechanism for fracture toughness improvement in metals. This work not only offers atomic-scale insights into the deformation behavior of nano-alloy materials but also provides new perspectives for the design of high-performance alloys with superior fracture resistance.

Two-dimensional tungsten disulfide (2D WS2) has attracted significant attention across diverse application fields, particularly optoelectronic devices and field-effect transistors, due to its exceptional properties. A thorough elucidation of the WS2 growth mechanism is crucial for device implementation, as it allows for precise modulation of the nanoscale properties. Despite significant efforts toward the growth of 2D WS2 for increasing its size, detailed investigations into its structural evolution, especially for the out-of-plane layered WS2, remain scarce. In this work, we identify two distinct conversion growth mechanisms for in-plane and out-of-plane layered WS2 using a homemade chemical vapor deposition (CVD) system. We systematically investigate the evolution of different WS2 nanophases by altering the precursor and regulating the sulphur concentrations. The results reveal that out-of-plane 1D and 2D WS2 are formed via an outside-in mechanism during the layer-by-layer sulphurization of WO2.7 nanowires, while in-plane layered WS2 evolves from WO3 precursors via a 'self-seeding' mechanism involving an island-like WO3-x-WS2 core-shell structure. This study clarifies the 2D WS2 growth process, offering key insights into the evolution mechanisms of low-dimensional WS2. These findings may not only pave the way for synthesizing high-quality, large-scale 2D-domain WS2 but also offer guidance for the controlled growth of other transition-metal dichalcogenides.

AuCu bimetallic nanocatalysts is one of the most widely applied heterogeneous catalytic system. However, the oxide layer induced by surface oxidation would block electron/mass transfer pathways, inducing complete catalyst poisoning. Although oxide growth dynamics have been extensively investigated, ​the nucleation mechanism governing initial oxidation remains elusive. Here, the initial oxidation dynamics of the AuCu system were deciphered through atomic-resolution environmental transmission electron microscopy (ETEM), which enabled real-time visualization of nucleation pathways at sub-Ångström spatial precision. The nucleation process involves complex oxygen-alloy interactions, progressing through three consecutive steps: (i) Atomic aggregation, (ii) Crystallization at the nanometer scale and(iii) Crystalline particle growth.This amorphous-to-crystalline transition follows a well-defined pathway: amorphous clusters → crystalline nuclei → polyhedral crystals→ single-crystal octahedra. Critically, small nuclei exhibit rotational dynamics when minimally integrated into the alloy matrix.​This behavior is governed by circuit diffusion through surface steps, corners, and defects​, with negligible contribution from bulk diffusion during initial oxidation. These atomic-scale insights elucidate the early-stage oxidation dynamics of AuCu alloys and provide a blueprint for designing corrosion-resistant catalysts.

High-fidelity intracellular sensing necessitates minimally invasive nanoelectrodes with precisely controlled tip geometries to mitigate cellular trauma and enhance signal stability. However, conventional etching techniques often struggle with the reproducible modulation of tip morphology, particularly the cone angle. In this work, we report a concentration gradient-controlled electrochemical etching (CG-CEE) strategy that facilitates the deterministic fabrication of carbon fiber nanoelectrodes with tailored geometries. By leveraging spatial confinement within a micro-capillary sleeve to restrict etchant diffusion, CG-CEE establishes a stable axial concentration gradient, enabling spatially regulated etching kinetics. Modulating the sleeve diameter allows for the precise adjustment of the concentration profile, thereby enabling the controlled fabrication of tip angles ranging from 6° to 40°. This robust and highly reproducible method not only provides specialized nanoelectrodes for real-time intracellular sensing but also exhibits exceptional versatility, as demonstrated by the fabrication of high-precision tungsten needles. The CG-CEE approach offers a powerful platform for the customized preparation of various nanotip electrodes in bioanalytical chemistry and micro-fabrication.

Long-period stacking ordered (LPSO) structures can enhance the mechanical properties of magnesium alloys by impeding dislocation motion and hindering deformation twin. In this work, we reported serrated twin boundaries (TBs) induced by LPSO-mediated twin impedance in room-temperature-processed Mg-Gd-Zn alloy and characterized the formation mechanisms at atomic-scale. For the LPSO structures with discontinuous or random spatial distributions in the matrix, TB bypasses the discontinuous LPSO structures, forming the LPSO/TB (basal-prismatic, BP) interfaces. Zn-enriched misfit dislocations formed at the LPSO/TB interface and exerted interfacial pinning on TBs. Reactions of matrix basal dislocations with TBs generate twinning dislocations accompanied by emission of partial basal dislocations and formation of stacking faults (SFs) in twin domains. These SFs also exerted a pinning effect on the BP interface. The synergistic effect of these factors generates serrated {1012} deformation twins and provides new insights into LPSO-twin interaction mechanisms.

Van der Waals (vdW) semiconductors are promising candidates for next-generation electronic devices. Although plasticity has been observed in these materials, strain hardening and large uniform tensile elongation remain elusive. Here we report that GaSe single crystals exhibit exceptional tensile ductility when loaded along directions inclined to the [0001] zone axis, achieving uniform tensile elongation exceeding 40% together with pronounced strain hardening. Using atomic-resolution, stress-quantified experiments, we uncover a delocalized interlayer shear mechanism in which alternating slip between adjacent vdW layers homogenizes tensile strain and suppresses localization. This cooperative slip process drives an ε-to-γ phase transformation and introduces constrained slip pathways, giving rise to a previously unrecognized vdW strain hardening mechanism. Comparable tensile ductility and strain hardening behaviour are further observed in other chalcogenides, such as InSe and SnSe2, suggesting the generality of this mechanism. These findings revise the mechanical paradigm of vdW semiconductors and establish a basis for their use in flexible and stretchable electronics.

The energy conversion paradigm of triboelectric nanogenerators (TENGs) has recently transitioned from suppressing electrostatic discharge (ESD) to actively exploiting it. In dielectric sliding triboelectric systems, ESD occurs across the entire sliding interface. While the conventional bi-characteristic current TENG (BC-TENG) successfully harvests side electrostatic discharge (SED), harvesting interfacial electrostatic discharge (IED) remains a bottleneck due to its stochastic location and poor coupling with external side collection electrodes. Inspired by the edge effect of the dielectric sliding interface, we propose a microstructure-designed BC-TENG (MBC-TENG) to achieve the synergistic harvesting of IED and SED. By constructing regular microscale surface structures on the stator, we create artificial edges that guide the chaotic IED to occur preferentially at these designated sides, effectively reorganizing the stochastic IED into a regular and controllable process. Coupling the microstructures with embedded electrodes enables the efficient superposition of IED and SED energy. The optimized device delivers an average power density of 14.9 W/m2 and an output energy of 3.92 mJ per cycle, achieving a 10.8-fold current enhancement over the conventional BC-TENG. Furthermore, the microstructureenhanced air ionization significantly reduces internal impedance and enhances load adaptability. This work provides a transformative methodology for regulating IED, offering a robust platform for high-efficiency mechanical energy harvesting.

Au-Cu bimetallic nanocatalysts is one of the most widely applied heterogeneous catalytic system. However, the oxide layer induced by surface oxidation would block electron/mass transfer pathways, inducing complete catalyst poisoning. Although oxide growth dynamics have been extensively investigated, the nucleation mechanism governing initial oxidation remains elusive. Here, the initial oxidation dynamics of the Au-Cu system were deciphered through atomic-resolution environmental transmission electron microscopy (ETEM), which enabled real-time visualization of nucleation pathways at sub-Ångström spatial precision. The nucleation process involves complex oxygen-alloy interactions, progressing through three consecutive steps: (i) Atomic aggregation, (ii) Crystallization at the nanometer scale and(iii) Crystalline particle growth.This amorphous-to-crystalline transition follows a well-defined pathway: amorphous clusters → crystalline nuclei → polyhedral crystals→ single-crystal octahedra. Critically, small nuclei exhibit rotational dynamics when minimally integrated into the alloy matrix. This behavior is governed by short-circuit diffusion through surface steps, corners, and defects, with negligible contribution from bulk diffusion during initial oxidation. These atomic-scale insights elucidate the early-stage oxidation dynamics of Au-Cu alloys and provide a blueprint for designing corrosion-resistant catalysts.

Carbon dots (CDs) offer several advantages, including non-toxicity, facile synthesis, high fluorescence efficiency, and large Stokes shift, rendering them up-and-coming candidates for luminescent solar concentrators (LSCs). However, the inherently weak light absorption of CDs significantly hinders LSC performance. Here, by modifying the space-confined vacuum heating method, we synthesized high quantum yield CDs with increased size and improved absorption cross section (up to 2.7 times greater than the smaller counterparts), which was elucidated by the size-dominated non-resonant absorption mechanism. The enhanced absorptivity at reduced concentration was demonstrated to mitigate aggregation-induced quenching effectively. Furthermore, we designed a multi-film coating structure to block and recycle the transmitted harmful ultraviolet and short-wavelength blue light through optical interference, thereby fully exploiting this ‘useless’ waveband. By optimizing both the CD absorption cross section and the blue light recycling, the fabricated 80 × 80 × 2.5 mm3 LSC device achieved a record-high external optical efficiency of 9.6%, while still maintaining 71% average visible transmittance. This work proves the substantial potential of enhancing the efficiency of CD-based LSC devices from the perspective of light absorption.

Nanotips exhibit a low turn-on field and high emission current density, and are considered promising candidates in future cold-field emitters. However, it is difficult to fabricate an emitter with ultra-fine curvature radius, outstanding collimation and stable interfacial adhesion. In this study, we developed an in situ technique that enables the fabrication of single-crystal hafnium carbide (HfC) nanotips on top of tungsten (W). The single-crystal feature and outstanding collimation of HfC nanotips were confirmed using transmission electron microscopy (TEM). In situ TEM investigation revealed that the HfC nanotip exhibited a typical field-emission turn-on voltage of 128 V (20 nA), and a significant current of ∼230 nA at a low extraction voltage of 149 V, when the distance between the tip and extractor is ∼50 nm. The field enhancement factor of the HfC nanotip was as high as ∼2 × 107 m-1. These exceptional properties can be attributed to the single-crystal feature, the nanometer-sized apex, the outstanding collimation and the stable interfacial adhesion of the HfC nanotip.